“It is said that a bile duct growth can be difficult to treat, partly because of the difficulty of detecting it early. In my case, luckily, it was detected very early and I had no symptoms,” he wrote. “I was counseled that removal at an early stage would be the desirable medical option. Therefore I had surgery last week, and I came through it well.”

Iwata,54 years old, missed the Electronic Entertainment Expo — one of the industry’s most prominent events — earlier this month in Los Angeles, citing advice from his physician, but had not disclosed the nature of his condition. He made an appearance in a video presentation, with his CG-alias taking on Nintendo of America President Reggie Fils-Aimé in a Smash Bros. battle sequence. During E3, Nintendo went on to unveil a blitz of new games aimed at saving itsstruggling flagship Wii U console and turn around the loss-making company.

The surgery comes at a key junction for Nintendo, which is experimenting with new business models and exploring new ventures, such as in healthcare and in emerging markets.

Iwata, who in 2002 became Nintendo’s first president unrelated to the founding Yamauchi family, said that he has already resumed business by email and other methods, but that it will take a little more time before he can return to his regular work schedule.

“As the president of the company, I regret that I cannot attend the meeting. However, I understand that I have to prioritize my medical treatment and to recover as soon as possible so that I will again be able to do my best to help the company to grow. I hope that you understand,” he concluded.